Referring to FIG. 1, a conventional hot-pressing molding machine 1 as disclosed in Taiwanese Patent No. M360124 includes a lower die 11, an upper die 12 movable relative to the lower die 11, and an enclosure 13 disposed to enclose the lower and upper dies 11, 12 for defining a vacuum chamber. An object or material (not shown) is heated and pressed in a mold cavity defined by facing surfaces of the lower and upper dies 11, 12 when the lower and upper dies 11, 12 are closed under a vacuum environment, so that even pressure and heat can be provided to prevent formation of bubbles in products.
Although such vacuum chamber facilitates the structural transformation or chemical reaction of an object or material under heating and pressing, heat radiation and heat conduction in a vacuum environment may cause damage to the upper die 12 or the lower die 11, or other component parts adjacent to the lower and upper dies 11, 12 due to high temperature. Hence, the maximum heat-resistance temperature of the hot-pressing molding machine is generally about 400° C. such that the hot-pressing molding machine cannot be employed to perform a heating and pressurizing process for a long period of time, such as a pyrolytic reaction of a non-graphitizable carbon material where a pyrolysis temperature of above 500° C. is required.